Abstract: A composition of a drug carrier, a pharmaceutical composition thereof, a preparation method and a use method thereof are provided. The composition of a drug carrier includes a first mixture and a second mixture. The first mixture includes a hydrophilic polymer, tricalcium phosphate and a water-soluble dispersant. The second mixture includes a water-absorbing material and a divalent cation salt. The pharmaceutical composition includes the composition of a drug carrier above and a drug for preparing an anti-inflammatory or antibiotic medicine. The preparation method of the composition of a drug carrier includes mixing the first mixture and the second mixture. The use method of the composition of a drug carrier includes mixing the first mixture with a drug and then adding the second mixture. Accordingly, topically applying the pharmaceutical composition on a surgical site may effectively release the drug thereon.